摘要
本文研究了40种中国重要木材流体渗透性的特点和规律。结果表明,针叶材纵向空气渗透性为0.00957—1.87173 darcy,阔叶材为0.00195—13.49867darcy;针、阔叶材边材渗透性比心材高;种间或种内渗透性高低与密度无关;研究的全部针叶材、约70％的环孔材和约30％的散孔材与半散孔材渗透性(以心材为准)均在0.1 darcy以下,属较低等级以下。针叶材低渗透树种比阔叶材多,与纵向单位长度上阻碍流动细胞间隔数在前者比后者多有关;环孔材低渗透树种比散孔材和半散孔材多,由于前者含有或多或少侵填体或树胶堵塞导管和管间纹孔所致。同类树种之间渗透性差异,针叶材决定于有效纹孔膜微孔半径和数量,大而多者渗透性高;环孔材除纹孔之外,还与侵填体或树胶有无和多少,甚至侵填体上微孔有无和多少及大小有关;散孔材或半散孔材,来源于管间纹孔膜微孔半径和数量、穿孔板的类型以及管孔的大小和数量的不同。
This paper dealt with the longitudinal air permeability of 40 important Chinese woods. Their perweable characteristics and laws were revealed. The air permeabilities measured at about 10％ M. C for softwoods were between 0. 00957 and 1. 87173 darcy,while for hardwoods were 0. 00195 to 13. 49867 darcy. The permeability of sapwood of both softwoods and hardwoods was much higher than that of heartwood. The permeability of wood was not related to its density in regardless of softwood or hardwoodand the same or different species. In the 40 species studied, the permeability of heartwood of all softwoods, about 70％ ring-porous and about 30％ diffuse porous or hemidiffuse porous woods was below 0.1 darcy, which belonged to a low range of permeability. The species of low permeability in softwoods were more than that in hardwoods because the numbers of cell cross per unit length in axial direction which hinder flow of fluid in the former were more than that in the latter. The species of low permeability in ring-porous woods were more than that in diffuse porous or hemidiffuse porous woods as a result of the existance of tylosis or gum which obstructed vessels and pit membrane openings between vessels. As far as softwood was concerned, the difference of permeability relied on the effective radius and number of pit membrane openings, as for ring-porous woods was also dependent on the existance and number of tylosis or gum in the vessels, even the number and size of openings in the tylosis in addition to the pit membrane openings between vessels, and as for diffuse or hemidiffuse porous woods resulted from the radius and number of pit membrane openings between vessels, the type of perforation plate contained in the vessels and the radius and number of vessels.
出处
《林业科学》
EI
CAS
CSCD
北大核心
1992年第3期237-246,共10页
Scientia Silvae Sinicae
基金
中国林业科学研究院科学发展基金
关键词
木材
流体
流量率
渗透性
Wood
Fluid
Flow rate
Permeability
